Treatments given to weaken and destroy breast cancer BEFORE surgery are called neoadjuvant treatments. Most neoadjuvant treatments are made up of one or more chemotherapy medicines. Targeted therapy medicines, hormonal therapy, or radiation therapy also occasionally are used as neoadjuvant treatments.

Treatment before surgery isn't routinely used to treat early-stage breast cancer, but may be used if the cancer is large or aggressive. When neoadjuvant treatment dramatically shrinks a cancer, lumpectomy instead of mastectomy may be an option for some women.

A study found that breast MRI (magnetic resonance imaging) before surgery was better at assessing how well a cancer responded to neoadjuvant treatment compared to more traditional assessment measures such as a physical exam, mammogram, or ultrasound.

The I-SPY Trials are a series of studies looking at the best ways to evaluate responses to breast cancer treatment. ACRIN 6657 is one study in the I-SPY Trials. In the ACRIN 6657 study, 216 women diagnosed with stage II or stage III (early-stage) breast cancer were treated with chemotherapy before surgery.

Besides using traditional ways to assess the cancers’ responses to neoadjuvant chemotherapy, all the women had breast MRI before, during, and at the end of neoadjuvant treatment, before surgery. The researchers compared each woman’s MRI results to the traditional measurements to assess treatment response.

Both during and after neoadjuvant treatment, MRI was better than traditional assessment measurements in determining treatment response. This included determining if any cancer was present after neoadjuvant chemotherapy and, if so, how large (in three-dimensions) the remaining cancer was.

Breast cancers need a good blood supply to deliver the oxygen and nutrients that it needs to grow and multiply. To get that blood, cancer cells have ways of stimulating the growth of new blood vessels in the tumor. This new blood vessel growth is called angiogenesis (“angio” means blood vessel and “genesis” means beginning). This study found that an MRI was able to detect decreased blood flow (reduced angiogenesis) over time, an important sign that neoadjuvant chemotherapy had weakened the cancer.

More precise information about the degree of response to neoadjuvant treatment could affect plans for surgery and treatments after surgery. For example, women for whom mastectomy was recommended might be considered eligible for lumpectomy if MRI shows the breast cancer is smaller and weaker than thought based on traditional assessments.

If you’ve been diagnosed with early-stage breast cancer and your doctor has recommended treatment before surgery, you may want to ask your doctor about this study. Ask your doctor how your response to neoadjuvant treatment will be assessed and how that information might affect plans for surgery and treatment after surgery. Accurate information about the cancer is essential to developing a treatment plan that makes the most sense for you.